Effect of exogenous nitric oxide on the growth and antioxidant enzyme activities of Lolium perenne under Cd stress

Lolium perenne seedlings were treated with SNP(a NO donor) 0.1 mmol/L,Cd2+ 200 mg/L and SNP 0.1 mmol/L + Cd2+ 200 mg/L.Compared with the CK,SNP at 0.1 mmol/L increased biomass amount,chlorophyll content and root activity,but decreased MDA content,generation rate and membrane permeability,while enhanced the antioxidant enzymes activities of L.perenne seedlings.However,200 mg/L Cd2+ decreased biomass amount,chlorophyll content and root activity,but increased MDA content,generation rate,membrane permeability,and accumulated Cd2+.The antioxidant enzymes activities decreased.Compared with Cd2+ 200 mg/L treatment,SNP 0.1 mmol/L promoted biomass amount,chlorophyll content and root vigor,but decreased MDA content,generation rate,membrane permeability and Cd2+ content of L.perenne seedlings,while increased the antioxidant enzyme activities of the seedlings increased under Cd2+ 200 mg/L stress.The results indicated that exogenous nitric oxide(NO) had a mitigating effect on the growth of seedlings under Cd2+ 200 mg/L stress,and enhanced the resistance of them to Cd toxicity.